Screw type comminuting apparatus



April 10, 1956 c. BGRNER 2,741,435

SCREW TYPE COMMINUTING APPARATUS Filed June 24, 1952 INVEN TOR.

hn'sfian 3o rnef BY Mew szym United States Patent g invention relates toa screw type cornatin ppa aws- M me particularly, the present inventionrelates to a c'omminuting apparatuslof the screw type which is adaptedto comminute material by rotation of the screw within a cylindricalenclosure located about the screw.

In devices of this type, particularly those which are used forindustrial purposes, it sometimes happens that the material beingcomminuted becomes tightly squeezed between the screw and cylinder whichresults in the requirement of an extremely great force to rotate thescrew and sometimesresults in -jamming'of;the screws so that the lattercannot be turned. These diff culties frequently an'se forexampleinfthecomminuting of materials such as alkali-cellulose. ;A furtherdisadvantage of such constructions is that they cause the material beingcomminutedto become un'desirablyoverheated so that they are not in asuitable condition for the further steps of a given chemical prbcs s,orthelike. 7

*It is'thtforea-general object of the present invention to provide ascrew type"comminutjng device with a means for comminuting the materialwith a force augmenting that o f'th efscrewandcylindersothat thematerial being comminute'd will not become'j'ammed or overheated and sothat the energy required to rotate the screw will be appreciablydiminished.

With this object in view, the present invention mainly consists of ascrew type comminuting apparatus which includes an elongated cylinderhaving an elongated screw located therein spaced from the inner surfacethereof, extending along the axis thereof, and being mounted in thecylinder for rotation about this axis. A plurality of pairs of oppositetransverse wall members are fixedly connected to the screw between theconvolutions thereof to form chambers within these convolutions, andeach of these wall members has an outer free surface portion facing theinner surface of the cylinder, spaced therefrom and graduallyapproaching the latter so as to form a nozzle with the inner cylindersurface so that material being comrninuted will be compressed againstthe latter.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, Willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings, inwhich:

Fig. l is a side sectional, perspective view of an apparatus constructedin accordance with the present invention; and

Fig. 2 is a fragmentary, perspective view of a part of the apparatus ofFigure 1.

Referring to the drawings, there is shown in Figure l a cylindricalenclosure 1 having at its right upper end, as viewed in Figure 1, aninlet and at its left lower end, as viewed in Figure 1, an outlet. Thiscylinder 1 is provided with opposite end walls which support, forrotation about 2,741,435 li rare-wee. one

'2 the axis of the cylinder 1, 'a sciew member 3 "located the cylinder 1"and being spaced from the inner surface thereof 'bya gap "6. This innersurfaceof cylinder 1 is provided with pyramidal teeth 2, as is clearlyshown in Figure 1. Between the convolutions of the "screw '3 were areprovided a plurality of pairs of opposite walls 5, whose constructionisim'ost clearly shown in Figure 2,

'all of the Walls 5 on 'one'sideof'the turning axisbfscrevv 3terminating in edges which are located along a' str'a'ig'ht line, andalong each of these straight lines there i's'iixed' 'toth'e screw member3 for rotation therewith a'toethed strip '4 which cooperates with theteeth '2 to cohfminute the material, this material first entering thechamber 7 or" worm 3 and then successively entering the chambers of WormSformed by walls-'5. l

As is shown most clearly in Figure 2, the "walls f5 each have "outersurface portions which face the inner cylinder surface of the cylinderland which gradually approach the same to form a nozzle 8 so that, whenthe screw is turned 'in the direction of the'arrow shown 'in Figuresland 2, thematerialbeing commin'uted is-forced by 'the outer surface ofWalls 5 against the inne'rcyli'ridrical 'surfaceto greatly increase the'cornminutin'g'acition of 'the device "so that overheating of thematerial and jamming of the apparatus is prevented. Also the ener'g'yrequired to operate the apparatus is greatly diminished. Although theseouter surface portions 'of Walls '5, which face the inner surface ofcylinder 8 and gradually approach the same, maybe fiat,inthepartic'ula'r example illustrated, these surfaces are convexly curved,

It will he understood that each of the element's described above, ortwoor more together, may 'alsofindfa useful application in other types *ofscrew type 'c omminuting apparatus "differing from the types describedabove.

While "I "have illustrated and described the invention as "embodied inscrew type 'comminutiug 'apparatusjfor :pdsitiirely compressing thematerial being commin'tited against the inner surface ofa casing of theapparatus, I

various modifications and structural changes may be made withoutdeparting in any way from the spirit of my invention.

Without further analysis, the foregoing will so fully reveal the gist ofmy invention that others can by applying current knowledge readily adaptit for various applications without omitting features that, from thestandpoint of prior art, fairly constitute essential characteristics ofthe generic or specific aspects of this invention and, therefore, suchadaptations should and are intended to be comprehended within themeaning and range of equivalence of the following claims.

What I claim as new and desire to secure by Letters Patent is:

I. A screw type comminuting apparatus comprising, in combination, anelongated circular cylinder; an elongated screw of constant radiusspaced from the inner surface of said cylinder, extending along thelength thereof, and being mounted within said cylinder for rotationabout the central axis of the latter; a plurality of transverse wallsfixedly connected to said screw between the convolutions thereof, eachextending from one convolution to the next convolution and each having aterminal surface portion at the same radial distance from said axis asthe screw periphery located adjacent to but spaced from the innersurface of said cylinder and defining a substantially wedge-shaped spacewith the inner surface of said cylinder to form a nozzle with thelatter, said terminal surface portions of said walls also defining withsaid inner surface of said cylinder a gap having a width which remainsconstant at all angular positions of said screw during rotation thereof;and projecting meansat the inner surface of said cylinder projectingtoward the screw and distributed about saidinner surface forparticipating in the comminuting action of the apparatus, so thatmaterial being comminuted within said cylinder during rotation of :saidscrew is compressed against the inner surface'of said cylinder andthrough the 'gap 'betweenthe same' and said walls so as'to be comagainstthe latter, the wall members on each side of said minuted with a forceaugmenting that produced hyfthe f screw and cylinder.

2. A screw type comminuting apparatuscomprising in combination, anelongated circular cylinder; an elon-. gated .screw'of'constant radiusspaced from the inner surface 'of said cylinder, extending along thelength thereof, and beingmounted withinsaid cylinder-for rotationaboutthe central axis. of the latter; a plurality of -pairs; of opposite,transversewall members fixedly con-' nected to'said'screw between and incontact with the con cylinder axis terminating in free edges which arelocated along a substantially straight line parallel to said axis; andan elongated toothed member fixed to said free edges of; said wallmembers and located at the outer surface of said screw extendingacross-the convolutions. thereof.

'4. A. screw type comrninutin'g apparatus as defined in claim 3 andwherein said inner cylinder surface is provided with a plurality of.teeth.

5. A screw type comminu'ting' apparatus comprising, i

in combination; an elongated cylinderhaving an inner cylinder surfaceprovided 'With'a plurality of teeth; an

volutions thereof to form separate chambers with said M convolutions,each of said wallmembers having an outer free terminal surface portionat the sameradial distance 'from said axis as the'scr'ew peripheryfacing said inner surface of'said-cylinder, being spaced therefrom anddefining a substantially wedge-shaped space therewith to membersalsodefining with said inner surface of said cylinder a gap having a widthwhich remains constant at all angular positions of said screw duringrotation thereof; and projecting means at the inner surface of saidcylinder projecting toward said screw and: distributed about-said innersurface of said cylinder for participating in the comminuting action ofthe apparatus.

. 3. A screw type comminuting apparatus comprising;

in combination, an elongated cylinder; an elongated screw claim 2 andwherein said outer free surface portion of each wall member is convexlycurved.

spacedfrom the'inner surface of said cylindergextending j alongthelength thereof and being 'mou'nted'within said cylinder for rotationabout thec'entral axis of the latter;

a plurality of pairs of opposite, transverse wall members fixedlyconnectedto said screw between and'in contact elongated screw spacedfrom the inner surface of said cylinder, extending along the lengththereof and being mounted within 'said cylinder for rotation about thecentral axis of the latter; and aplurality of pairs of opposite,transverse wall members fixedly connected to said screw between and incontact with the convolutions thereof to form separate chambers withsaid convolutions, each of said wall members having an'outer freeterminal surface portion facing said inner surface of said cylinder,being spaced therefrom and defining a substantially wedge-shaped spacetherewith so as to form a nozzle with said inner cylinder surface sothat material being comminuted'will'be compressed against the latter;

6. A screw type comminuting apparatus as defined in References Citedin'the file of this'patent UNITED STATES PATENTS 2,476,335 Tusson July19, .1949

FOREIGN PATENTS 443,481 Great Britain Feb. 28, 1936 455,908 Germany Feb.11, 1928

